Heat-treating machine



.July 27 1926. 1,593,950

J. A. PERSON HEAT TREATING umcanm.

Filed May 23"; 1921 3 Sheets-Sheet 1 July 27,1926. l 1,593,950

J. A. PIERSON 7 HEAT TREATING MACHINE Filed May 23, 19m s Sheets-Sheet 2 John dZZber?Zh'eraon/.

July 27 1926. 1,593,950 J. A. PIERSON HEAT TREATING MACHINE 3 Shets-Sheet 5 Patented July 27, 1926.

' UNITED STATES PATENT-OF FICE. I

GEORGE E. GILMAN, OF BELMONT, MASSACHUSETTS.

HEAT-TREATING? MACHINE.

Application m m 23,

My invention pertains to heat treating machines and particularly but not exclusively to machines for heat treating drill steels.

My invention will be best understood from the following description when read in the light of the accompanying drawings of one specific embodiment of my invention selected for illustrative purposes, while the scope of my invention willbe particularly pointed out in the appended claims.

In the drawings Fig. 1 is a plan with parts broken away of a machine constructed according to my invention;

Fig. 2 is a fragmentary section on the line 22 of Fig. 1;

Fig. 3 IS an elevation of the carrier looking at it from the right in Fig. 2;

- Fig. 4 is an elevation of the lower ortion pf 'the'carrier looking at it from the rlght of Fig. 5 Fig. 3; I Fig. 6 is a"section on the line 66 of lg. 4' I I Fig. 7 is a section on the line 7-7 of 1g. 2 I Fig. 8' is a section on the line 8-8 of i 1 I Fig. 9 is a more or less diagrammatic development of the machne; and

Fig. 10 is a more or less diagrammatic plan according to Fig. 9.

Referring tothe drawings drill steel is indicated at a, I have shown ais a section on the line 55 of plate 1, bent in theform of a cylinder and having parallel upper and lower edges 3 and 5 forming tracks for the upper and lower wheels 7 and 9 of the drill steel carriers.

Circumferentially distributed around the machine and under the tracks are a loading table 11, a furnace 12, and a quenching tank a 13, the tracks as illustrated by Fig. 9 being at different levels adjacent these instrumentalities, which levels are connected byinclined portions of the track so that the carriers when moved in the direction of the arrow (Fig. 9) move the steels to lower them from the loading table to bring their end Qportionsi into the furnace and after removing the end portions of the steels from the furnace lower them into the quenching tank 'and after passing them through the tank raise the'mfout of the tank and' move them in which the 7 general operation of the machine can understoodc by reference to Figs. 9 and 10.

1921. Serial No. 471,864.

past the mechanism 15 for disengaging the steels from the carriers, the carrlers finally being raised to the level of the loading table so that new steels may be placed thereon as the carriers move by the loading table.

The carrier is in the form of a casting having a leg 17 carrying the wheels 7 and 9 and a leg 19 connected to the leg 17 by means of the cross bar 21, the U-shaped structure so formed straddling the trac At the center of the cylinder formed by the track is a rptatableshaft 23 carrying a turret 25, thelatter being provided with an 'with an undulating circular cam track 41 b I means of a compression spring 43,,whic 1 constantly tends to force the heads 37 out- "wardly. Extending longitudinally of the outer face of each head 3 is a lug 45 and a lug 47, the latter projecting from the face a greater distance than the former, while for engagement with these lugs each leg 17 of the carriers is rovided with the lug 49 extending througli the heads,-the turret is provided with upstanding guides 51 engaging opposite sides of the head. i

out its length.- For guiding The construction of the cam 41 and the be best Thecam 4 1 is so constructed that both the' lugs 45 and 47 of the propeller are caused to engage the sides of the lug 49 of the carrier when the carrier is passing over the loading table. In this position, in a manner hereinafter described, the drill steel is placed on the carr'er'which is immediately moved down the inclined'portion of the track to the level above the furnace, where the cam surface 41 causes the propeller move inwardly in a radial direction to completely disengage the lug 49, the propeller however remaining in engagement long enough to push theyrow of carriers over the furnace forwardly ,dis-

tance equal to the width of one carrier,

which it is able to" do by reasonof the fact that the carriers at this time abut each other.

4 The propeller head now moves by the row of carriers over the furnace until it comes to immediately following the one under consideration lowers another carrier and drill steel into the furnace and finishes pushing the row of carriers along a distance equal to the width of one carrier in the manner just explained. The carrier at the end of the furnace which has been engaged by the propeller, as has just been described, is pushed along until it reaches the inclined portion of the track leading down to the level of the track above the quenching tank, whereupon it rolls down the inclined portion of the track by gravity advancing ahead of the propeller. When it reaches the end of the incline, it is stopped by means hereinafter described and remains stationary until the propeller again catches up with it, when the cam track 41 causes both lugs 45 and 47 to engage lug 49. The carrier, after moving the drill steel through the quenching tank, reaches the inclined portion leading to the level of the loading table and at this level or immediately before it reaches the level, the steel is disengaged from the carrier by the disengaging mechanism.

For causing" the carriers to come to rest when they run down the incline from the furnace to the quenching tank, the turret is provided with four radial outwardly extendmg arms 53, each of which extends into the path of the projection of the carrier when the latter is at the level corresponding to the beginning of-thequenching tank. This arm carries a suitable buffer member in the form of a bolt 57, having a head 59 anda compression spring 61 interposed between the arm and the head. The buffer is so located that it is in proper position for the carrier to strike it immediately upon reaching the bottom of the incline, the portion of the track at this point being preferably horizontal in order to insure the carrier remaining stationary until the propeller head again catches up to it.

As an example of the practice of my invention, but .without limitation thereto, I have found it practical to heat the cutting ends of the drill steels for a distance of-about four inch-es back from their end. For quenching them I preferably harden the tip by immersing it suddenly into the quenching liquid, say for example, for about fiveeighths of an inch, after which I gradually lower the remaining heated portion into the quenching li uid. For this purpose, the

hack, except or the short length thereof at the beginning of the quenching tank, is incline d downwardly, so that after the carrier begins to move. over the quenching tank, it gradually lowers the drill steel into the quenching liquid. It will be noticed that this sudden immersion of the heated end is caused to "take place by causing the drill steel to run down the incline to the level above the quenching tank and that the carrier is prevented from moving ahead of the propeller while traveling over the inclined portion of the track above the quenching tank by reason of both lugs 45 and 47 being in engagement with the carrier at that time.

In my present invention the bottom portion of the tank is filled with water or brine and on the same rests a layer of oil of less density than water or brine. The'oil preferably is of suflicient depth to. cause the tip of the heated end first plunged into the tank to a depth of five-eighths of an inch in the example given, to be quenched exclusively by the oil. Further immersion of the drill steel immediately brings the tip into the water or brine, which acts to keep cool the part which has been quenched by the oil and to quench the remaining portion of the heated end.

For keeping the contents of the tank cool, I provide a cooling coil which is immersed in the liquid. This coil comprises the headers 62 located at opposite ends of the.

quenching tank and the pipes 64 in fluid communication with the interior of the headers and arranged at opposite sides of the path of the drill steel. A suitable; intake 66 is provided for one header and arsimilar outtake connection for the other, inorder that cooling water may be led through the coils.

For holding the drill steels on the carrier, 1 provide a clamp at the lower end thereof and above this one or more additional gripping means. As illustrated, the intermediate portion and upper end of the carrier leg 19- are provided with the integral projections 63 and with movable clips 'cooperatdrill steel therebetween, each clip 65 as shown byFig. 7 being provided with the flared portion 67 the portion 69 adapted to approximately conform with the surface of the drill steel, and the portion 71 bent to form an eye through which passes the shaft 78 providing a pivot for the two clips. For holding the clips resiliently against the drill steel, 1 provide the coiled torsion springs mg with such projections for holding the through the coil of which the shaft passes and having opposite ends 77 and 79 extended respectively to engage the clip and the body of the leg. The portion 81 of the clip immediately adjacent the portion engaging the the leg to limit the movement of the clip towards the projection 63, the leg adjacent .drill steel, forms a shoulder which engages V for the portion 81 of site walls of the recess plroviding abutments t e clip and the end 77 of the spring. .As will be obvious, by

pressing the drill steel against the flared portion 67 of the clips, the springs will permit the clips to yield so that the 'steel ma snap into the portion 69 of the clip.

The lower portion of the leg 19 ,is provided with a projection 83 similar to the projections 63' above, the adjacent portionof the leg bein cut away to form half the bearin for t e rock shaft 85, the latter being held'in position by a bearing block 87 bolted to the leg at 88 and providin the other half of the bearing. On the side of the rock shaft adjacent the drill steel and radially extending from the shaft I provide a jaw 89 for engagement with the drill'steel and for securely clamping the steel between it and the projection 83-.- The opposite side of the rock shaft I provide with a member 91 providing oppositely extending levers 93 and 95, the ends of these levers cooperating with the oppositely inclined cam surfaces 97 and 99' rovided by inclined surfaces of the wedge-s aped opposite end portions of the vertically sliding member 101. 1 1 1 v Slidably mounted on the leg 19 in the lugs 103 is a rod 107, the latter carrying an abut-.

ment 109 for the s ring 111 having its other abutment against t eupper lug 103. To this rod isattached the member 101 which is thereby forced by the spring constantly in a direction tendin to cause the cam surface 97 to engage the ever 93 and to move the jaw 89 into the drill steel engaging position. For causing the jaw to release the drill steel,

I provide-a stationary cam 113 in the form of a bar supported in any suitable manner and located to have its upper surface in ensfandard 116 supporting hooked-shaped cam arms 117 the ends of which are adapted to .pass between the leg 19 and the drill steeland by motion of the carrier cause the arms to disen age the steel from the ripping means a orded by the clips 67, t e arms for this purpose providing surfaces 118 for engaging the drill steel, which are inclined outwardly as is illustrated by Fig. 1. Pref- .erably, the clips are disengaged before the jaw 89 disengages the steel, in order to cause the drill steel to pivot in. the clamp a'florded by the jaw so that it will fall out-' wardly away from the machine.- For this purpose, the steel engaging surface of the jaw preferably is made smooth and the'bar 113 is so located as to delay thev release of thejaw until after the clips are disengaged from the steel and the upperend of the steel has moved outwardly; some distance; The

carrier catches u bar 113 is provided with a beveled end sursquare end in order that the wedges may be released suddenly to cause the jaw to snap into engagement with the steel after the same has been inserted in the carrier and as it passes over the loading table.

Although I have described one form of my invention for purposes -of' illustration, it is understood that my invention is not limited thereby to particulardetails of construction but that wide deviations from the. same maybe made without departing from the spirit of my invention.

Claims: p

1. In a heat treating machine for the ends ofdrill steels, a heater, a tank containing a quenching liquid, carriers for the drill steels,

said tank for causing the drill steels to be] immersed gradually in said uenehing hquid as the carriers traverse sai pro eller forv moving said, carriers along surface 115 of the cam ortank, a"

end of the bar over the loading table has a no ortion' forguiding .said I sai track, said propeller having means for pushing said carriers on said first mentioned downwardly inclined portion of said track whereby they run down said inclined, portion of said track by gravity advancing faster than said propeller and plunge the tips of the ends of saidjsteelsin said quench- .mg' liquid and remain stationary until said to them, and means. for-* locking said carriers to said propeller while sald carriers move over the. second mentioned downwardly inclined portion ofsaid v. 2. In a heat treating'mac'hine forthe ends]. of drill v steels,-a heater, a-tank containing track.

a quenching liqu'id,"v carriers for "the"drillf-1 steels, a track for said carriers"havina'fz't. downwardly inclined. portionlfor guiding;

said carriers fromsaid heaterto said. tank and having a downwardly inclined portion over said' tank for causing the drillsteels to be"immersed'gradually in said; queriching liquid as the carriers traverse} said tank, .a propeller for movingjsaid c ar riers along said track, said ,propeller'having,

means for pushing said carrier-son sa id first mentioned downwardly inclined portion of. 'said'trackfwhereby they, rundown said' inf- 5"" clined portion-of said track by gravity ad vancing faster their-said. propeller and plunge the tips of the-ends of said steels in .sa'id quenching: 1iquid,:';,,stqp means fo ea'rresting motion of said carrier's when they reach said tank whereby said propeller is enabled to catch up to them, and means for locking said carriers to said propeller while said carriers move over the second mentioned downwardly inclined portion of said track.

3. In a heat treating machine for the ends of drill steels, a heater, a tank containing a quenching liquid, carriers for the drill steels, a track for said carriers having a downwardly inclined portion for guiding said carriers from said heater to said tank and having a downwardly inclined portion over said tank for causing the drill steels to be immersed gradually in said quenching liquid as the carriers traverse said tank, propelling mechanism for advancing said carriers along said track, said mechanism havving means for pushing said carriers on said first mentioned downwardly inclined portion of said track whereby said carriers run down said inclined portion by gravity and plunge the tips of the ends of said steels in said quenching liquid, said propelling mechanism having a stop for said carriers for causing them to come to rest upon reaching said tank, and said propelling mechanism locking said carriers thereto for movement on said second mentioned downwardly inclined portion of said track after said carriers remain stationary at said tank for a predetermined time.

4. In a heat treating machine for the ends of drill steels, a. heater, a tank containing quenching liquid. carriers for the drill steels, means for moving said carriers to causethem to traverse said heater and tank comprising a downwardly inclined track for guiding said carriers and drill steels from said heater to said tank, said means moving said carriers on said downwardly inclined track and permitting them to run down said trackvby gravity and plunge the tips of the heated ends of the drill steels in said quenching liquid, said means having a stop moving in the same direction as said carriers when traversing said tank for bringing said car- ,riers to rest when they reach said tank, and

said means efiecting locking of said carriers thereto after they have remained stationary at said tank for a predetermined time for moving the ends-[of the drill steels through said quenching liquid.

5. In a heat treating machine for the ends of drill steels, a heater, a tank containing quenching liquid, a closed track traversing said heater and tank,'carriers for drill steels movable along said track, propelling mechanism for said carriers comprising carrier engaging members moving generally parallel to said track, said track having a down- 'wardly inclined portion down which said carriers move by gravity to plunge the tips of the ends of drill 'steels in said quenching liquid and 'a downwardly inclined portion carriers, said carrier engaging members having a pair of lugs one of which engages said carriers for pushing them on said first mentioned downwardly inclined portion of said track for allowing them to run down said inclined portion by gravity and advance ahead of said members and both of which engage said carriers after said members catch up to them for moving them over the second mentioned inclined portion of said track.

6. In a heat treating machine for the ends of drill steels, a heat treating instrumentality, a carrier for moving drill steels to be treated relatively to said instrumentality, means for guiding said carrier, a propeller for moving said carrier along said last named means, and means for connecting and disconnecting said carrier and propeller for respectively enforcing movement of said carrier at the same rate as said propeller and for permitting said carrier at times to move relatively to said instrumentality at a different rate than said propeller.

' 7. In a heat treating machine for the ends of drill steels, a heat treating instrumentality, a carrier for moving drill steels to be treated relatively to said instrumentality, means -for guiding said carrier. a propeller for moving said carrier along said last named means, and means responsive to movement of said propeller for connecting and disconnecting said carrier and said propeller for respectively enforcing movement of said carrier at the same rate as said propeller and for permitting said carrier at times to move relatively to said instrumentality at a "different rate than said propeller.

8. In a heat treating machine for the ends of drill steels, a heat treating instrumentality, a carrier member for moving drill steels to be treated relatively to said instrumentality. means for guiding said carrier. a propeller member for moving said carrier along said last named means, and means responsive to movement of one of said members for connecting and disconnecting said members for respectively enforcing movement of said carrier at the same rate as said propeller member and for permitting said carrier at times, to move relatively to said instrumentality at a different rate than said propeller member.

QYIn a heat treating machine for the ends of drill' steels, a heat treating instrumentality, a carrier for moving drill steels to be treated relatively to said instrumentality, means for guiding said carrier, a propeller for moving said carrier along said last named means, means normally connecting said carrier and propeller for preventing movement of the former faster than the lat ter relatively to said instrumentality, and means for at times disconnecting said carrier and propeller forcausing the latter to push the former along said guiding means and for permittingmovement, of said car,- rier faster than said propeller.

10. Ina heat treating machine for the ends of drill steels, a heater and a cooler, carriers for moving drill steels to be treated relatively to said heater and cooler, means for guiding said carriers, a propeller for moving said carriers along said last named means, means for normally connecting said carriers and pro eller to prevent movement of the former aster than the latter, and means for causing said propeller to advance faster than said carriers when the latter are at said heater and said carriers to advance faster than said propeller when said carriers move from said heater toward said "cooler.

11. In a heat treating machine for the ends of drillsteels, a heat treating'instrumentality, a carrier for moving drill steels to 'be'treated relatively to said instrumentality, a propeller for moving said carrier rela- ,tivel to said instrumentality having lugs of d fierent'lerigth, and meansfor causing one or both lugs to engage the carrier for sai carrier to said propeller.

12, ha heat treating machine for the ends of drill steels, a heat treating instrum'ejntality, a carrier for moving'drill steels to be treated relatively to said instrumentality, a propeller for moving said carrier relatively: to said instrumentality having lugs ,of different length, means'tfor causing one or both lugs to engage the carrier for respectively pushing said carrier ,or locking saidcarrier to said propeller, and means for withholding engagement of the carrier by both lugs for permitting said carrier to moye at a di' erent rate of speed relatively to sald instrumentality than said pro eller.

'13. In'a heat treating "mac ine a heater,

a cooler, a carrier for drill steels or the like for moving them relatively to said heater and cooler, means for guiding said carrier to bring-said steels progressively into thepresence of said. heater and said cooler, a propel- V ler for said carrier hav-ing means for moving said carrierinto said heater-and for then disengaging it and causing it to push another carrier out of said heater, means for causing the last named carrier to advance more rapidly than said fropellerto bring asteel into the presence 0 said cooler and then permit said propeller to overtake-it, and means for loc'kingjsaid propeller-to said carrier when said carrier is in the last named position and is overtaken. by said propeller. 14. Ina heat treating 'ihg ltankia carrier.for drill steels or/the I end: of drill steels, a

machine, a. quenchfowvingem-weielrr respectively pushing said carrier or locking .to permit track.

a downwardly inclined track for said carrieradjacent said tank, a propeller for said carrier and having movement lengthwise of said track, and means for connecting said portions, means for pushing said carrier out of said heater to cause it to run down said inclined portion, means for propelling said carrier along the portion of said track adjacent said cooler and for locking said carrier to said propelling means.

16. In a heat treating machine, a heater and a cooler, a carrier for drill steels or the like, a track for said carrier having a portion adjacent said cooler at a lower level than the portion adjacent said heater and a connecting inclined portion, propelling means for moving a carrier into said heater and for pushing a carrier out of said heater on said adjacent track portion to cause it to rundown said inclined portion, and means for then causing said carrier to remain stationary for a period and for afterwards locking it to said propelling means for moving it along the portion of track adjacent said cooler. 17. In a heat treating machine aheat treating instrumentality, a carrier for mov-" ing the article to be treated relatively to said instrumentality, a track forsaid carrier having an inclined portion and connecting portions at higher and lower levels, peller for causing said carrier to run by gravity down said inclinedportion," a stop at the lower track level for causing said carrier to come to rest,'and means for moving said-stop out of the path of said carrier its further. movement along said 18. In a heat treating machine, a heat treating instrumentality, a carrier for'movingsthe article to be'treated relatively to said" instrumentalit atrack for Said'carrier having an incline portion and connecting portions at higher and lower levels, r0

pelling means having a stop projecting into the path ofthe carrier: and at the lower level and having a carrier engaging portion, means'for causing said enga 'ng portion to push said carrier down sai inclined portion of track to caus'e said garrie'r to advance ahead of "said engaging portion and be brought to rest by said sto and'means for "afterwards connecting sai carrier to said propelling means.

19'. In a heat treating 'maiiihine' for the heater, a cooler,

a profor moving drill steels through said heater and cooler comprising carrlers for said steels and a circular track for guiding said carriers by said heater and cooler, said track having a downwardly inclined rtion for guiding said carriers from sai heater to said cooler, a rotary shaft surrounded by said track, a propeller head and a stop carried by said shaft in angularly spaced relati'on whereby said head may push said carriers on said downwardly inclinedportion and said stop may arrest motion of said carriers after they move down said inclined portion by gravity.

21. In a heat treating machine for the ends of drill steels, a heater and a cooler, a circular track traversing said heater and cooler, a carrier for moving the drill steels relatively to said heater and ,cooler mounted on said track, a propeller for said carrier having a uniform circular movement; and means for varying the rate of movement of said carrier relatively'to said heater and cooler comprising mechanism for causing said carrier to be at times connected to said propeller for like movement, at times disconnected from said propeller, and at times to be pushed by said propeller.

22. A heat treating machine for drill steels, having in combination, a heat treating instrumentality, a conveyor for moving said drill steels relatively to.said instrumentahty, means for fastening said steelsto said conveyor, sald means comprising "a.

movable jaw having a smooth gripping sure far-e, means for moving said jaw to release said steel, and means for forcibly moving said jaw to grip said steeL' 23. A heat treating machine for drill steels, having in combination, a heat treating in'strumentality, a conveyor for moving said drill steels relatively to said instrumentality, means for fastening said steels to said conveyor, said means comprising a. movable jaw, a lever for moving said jaw, a cam carried by said conveyor for operating said i jaw, and-means for operatin ,sa-id cam.

24. A heat treating mac 'ne for drill steels, havmgm combination, a "heat treatin instrumentality, a conveyor for moving" sai drill; steels i elatively to said instrumental 1ty, me as fol-fastening Ba d steels tos d jaw, a spring conveyor; said means comprising a movable jaw, a cam follower for operating said jaw,

cam means cooperating with saidfollower for moving said jaw to grip and release said steel, and means independent of the conveyor for actuating said cam means.

26. A heat treating machine for drill steels, havingin combination, a heat treating instrumentality, a conveyor for moving said ,drill steels relatively to said instrumentality, means for'fastening said steels to said cnnveyor, said means comprising a movable jaw, and a wedge for operating said aw.

27. A heat treating machine for drill steels, having in combination, a heat (treating instrumentality, a conveyor for moving said drill steels relatively to said instrumentality, of means for fastening said steels to saidconveyor, said means comprising a movable jaw, a wedge for operating said jaw, a spring for moving said wedge, means for compressing said spring and for releasing it after such compression wedge.

28. A heat treating machine for drill steels, having in combination, a heat treatin instrumentality, a conveyor for'moving sai drill steels relatively to said instrumentality, means for fastening said steels to said conveyor, said meanscomprising a movable for operating said jaw, means for compressing said spring and for releasing it to operate said aw to grip the steel, and means for increasing 'the mechanical advantage of said spring.

instrumentality, a conveyor for moving sai drill steels relatively to said instrumental- -ity, means for fastening said steels to said conveyor, said means comprising a movable a w, a ivoted member carrying said aw,

means, providin a pair of levers projecting from said mem er, cams cooperating with each lever, a. spring, means for moving one of said cams to operate one of'said levers 30.1n' a. 'heat treating machine heat,

to actuate said heat treating machine for *drill steels, having in combination, a heat treatin treating finstriimentalit a cartie: for mo ng he v relatively t plurality of clips for. gripping said steel and smooth jaws for spaced points intermediate said steels,

strumenta-lity,

carried by said shaft, and resilient means for moving said clips toward their steel en gaging position.

31. In a heat treating machine, aheat treating instrumentality, a drill steel carrier for moving drill steels relatively to said instrumentality, a clip and a clamp with gripping a drill steel at its length, means responsive to motion of said carrier for pulling said drill steel out of said clip .and tilting said steel relatively to said carrier about a point gripped by said jaws, and means for releasing said jaws after said drill steel has tilted.

32. In aheat' treating machine fort-he ends of drill steels, a heat treating instrumentality, a conveyor means for moving drill steelsrelatively to said instrumentality, means for clamping the drill steels to said conveyor means comprising a jaw, means for actuating said jaw comprising a spring pressed member having the cam surfaces 97 and 99, the levers 93 and 95 cooperating with said cam surfaces, motion'of said conveyor means for actuating said spring pressed member.

33. In a heat treating machine for the ends of drill steels, a heat treating instrumentality, a drill steel carrier, a, track for guiding said carrier relatively to said ina propeller head having the lugs and 47 for engaging said carrier; and means for moving said propeller head relatively to said carrier for causing both lugs 45 and 47 to engage said carrier in one position of said carrier on said track, onlythe lug'47 in another position, and neither lug in still another position of said carrier.

34. In a heat treating machine for drill. steels, aheater for heating the ends only of said steels, a quenching tank containing a body of water having a layer of oil thereon, and means for removing drill steels from said'heater and moving them to said quenching tank, said means first placing the tips only of the heated ends of the drill steels .into said oil for, quenching said tips and afterwards-subjecting said heated ends to said water. j

35. In a heat treating machine for drill steels, a heater for heating the ends only of means for removing said steels from said heater and quenching the tips only of the heated ends of the steels in oil and afterwards subjecting said heated ends to water. i

' 36. In a. heat treating-machine for drill and means respons ve to steels, a heater for of said steels, means for removing said steels from said heater and quenching the tips only of the heated ends of the steels in oil and afterwards gradually subjecting said heated ends to water. I v

37. In a heat treating machine, ing tank containing a body of water with a layer of oil thereon, means for first quenching the tip of a previously heated end of a drill steel in said oil and for afterwards moving said steel through said tank and for gradually immersing said end through said oil into said water.

88. In a heat treating machine, a quenchw ing tank, means for moving a drill steel through said tank, and a conduit for cooling fluid-at the side of path of said steel.

39. In a heat treating machine for drill steels, a heater for heating the ends of the drill-steels, a quenching tankcontaining a body of water having a layer of oil thereon, means for removing drill steels from said heater and suddenly plunging a p'redeter mined portion of their heated ends in said layer of oil only, said means maintaining said predetermined portion of said heated ends in said oil until said; predetermined portion is hardened and then gradually immersing said heated ends in said water. 40. In a heat treatingmachine for drill steels, a heatenfor heating the ends of the drill steels, a quenching tank containing a body of Water having a layer of oil. there- 'on, means for removing drill steels from said heater and suddenly plunging a predetermined portion of their heated ends in said layer of oil only, saidmeans maintaining the drill steels stationary until the portions thereof immersed in said oil are'hardened and then moving the drill steels laterally through said tank while gradually lowering their heated ends into said Water.

41. In a heat treating machine for drill steels, a heater, a quenching tank containing heating the ends only a quencha body of water with a layer of oil thereon,

means for moving the ends of drill steels through said heater, means for removing the drill steels from said heater and suddenly plunging a predetermined portion of their heated ends in said oil, said means maintaining said predetermined portion of the heated ends in said oil exclusively until said predetermined portions are hardened and then moving the drill steels laterally through said tank while graduallylowering the heated ends into said water.

In testimony yvhereof, I have name to this specifica'tion.

JOHN ALBERT PIERSON.

signed my 

